The invention relates to an actuating device for a manual transmission having a clutch unit of a commercial vehicle, including transmission control elements for mechanical actuation of the manual transmission and clutch control elements for actuation of the clutch unit by a fluid medium.
The sphere of application of the invention extends primarily to commercial vehicle construction. A central feature of many manual transmissions of commercial vehicles, especially for local and goods delivery traffic, long-distance transportation and also for intercity bus and coach traffic, is the auxiliary range transmission design having a plurality of gear steps. This construction is increasingly used for automatic manual transmission (AMT) on commercial vehicles. Thus, there are automatic 12-gear-three-range transmissions with PowerShift, for example.
Manual transmissions for commercial vehicles may, in principle, have varying degrees of automation. Here, the actuation of the shift clutch and the gear selection may be automated, depending on the type of driveaway mechanism. In manually shifted transmissions none of these mechanisms is automated, in semi-automated manual transmissions one of these mechanisms is automated and in the fully automatic manual transmissions of interest here all mechanisms are automated. From this arises the need to use suitable actuating devices for an automated driveaway clutch, an automated declutching when shifting gear and an automated gear selection and engine management.
The generally known way of allowing automated clutch actuation and automated gear selection is through the use of various control elements in the form of electro-pneumatic, electro-hydraulic and electro-mechanical actuators. In generally known automated manual transmissions use is made of so-called clutch control elements and transmission control elements, which are arranged in or on the manual transmission.
WO 2011/069526 A1 sets forth a commercial vehicle transmission, which is of a dual-clutch transmission type. Such a transmission concept may call for two physically separated transmission control elements in the form of actuators for automated actuation of the internal gearshift elements, such as gearshift rods, gearshift forks, dog clutches, synchromesh mechanisms and the like, integrated in the transmission. Here, in this case one of the transmission control elements may also serve for controlling the dual clutch by means of a fluid control medium. Furthermore, this type of transmission may also contain a central synchromesh mechanism, the actuation of which can likewise be performed by a transmission control element. Here, the choice of fluid control medium for these functions is basically between compressed air and hydraulic oil.
The physical separation of the various transmission control elements and the associated electronic transmission control requires a correspondingly large overall space on the transmission and/or clutch housing and a corresponding assembly outlay, especially for the pressure line connection.
The object of the invention, therefore, is to provide an actuating device of compact construction for an automated manual transmission, having at least one clutch unit, which can be easily and compactly fitted in or on the transmission housing.
This and other objects are achieved by an actuating device for a manual transmission with at least one clutch unit of a commercial vehicle, having transmission control elements for mechanical actuation of the manual transmission and clutch control elements for actuation of the clutch unit by a fluid medium. At least two operating cylinders serving as transmission control elements for actuating the manual transmission coupled thereto, together with at least one compressed air connection serving as clutch control elements for actuating the clutch unit connected thereto, are arranged in a common carrier housing.
The invention embraces the technical teaching that at least two operating cylinders serving as transmission control elements for actuating a manual transmission coupled thereto, together with at least one compressed air connection serving as clutch control elements for actuating a clutch unit connected thereto, are arranged, functionally integrated, in a common carrier housing of a modular actuating device.
The advantage of the solution according to the invention lies, in particular, in the fact that all sub-function units for actuating the manual transmission and at least the one clutch unit connected thereto are accommodated inside the common carrier housing of what constitutes one actuating device of compact construction, and can be integrated into an automated drivetrain of a commercial vehicle via corresponding fluid, mechanical and electrical interfaces. The high degree of functional integration and the resulting space-saving design allow the actuating device according to the invention to be fitted both in and on a transmission or clutch housing. The actuating device can therefore be described as a module which can be fitted and replaced separately as a self-contained unit.
According to a preferred embodiment of the invention, the operating cylinders for mechanical actuation of the manual transmission are arranged axially parallel at a distance from one another in the carrier housing. The operating cylinders serve for mechanical actuation of the gearshift mechanisms in the automated transmission, for which corresponding coupling points are provided on the manual transmission.
At least one further operating cylinder, which can be used for the synchronization of transmission components, is preferably arranged in the carrier housing next to the two aforementioned operating cylinders. For reasons of overall space, the axis of this additional operating cylinder may be offset parallel to the effective axis of a gearshift element corresponding to this in the transmission. In this case both axes are preferably connected to mechanical coupling elements.
In order to control the operating cylinders integrated in the carrier housing pneumatically with compressed air, the carrier housing preferably includes directional control valves assigned to these.
Besides the one compressed air connection serving as a clutch control element for actuating the clutch unit connected thereto, according to the preferred embodiment the carrier housing includes a further compressed air connection, in order to actuate a further clutch unit of an automated manual transmission, for example. In this case the compressed air connections may preferably each, in turn, be divided into a ventilation aperture and a venting aperture.
For compressed air control, multiple, integrated directional control valves, the working connection of which opens at an associated compressed air connection, are preferably provided in the carrier housing.
The functionally integrated actuating device further includes an electronic unit, which is preferably arranged on the base of the carrier housing and which serves as an electrical interface for external transmission and clutch control of the manual transmission. An electrical wiring harness can be connected to the electronic unit.
The carrier housing of the actuating device is preferably designed as a divided diecast component, in which pneumatic ducts are integrally formed for ducting the compressed air. Additional pneumatic connecting lines inside the carrier housing are in as much eliminated. The inasmuch functionally integrated carrier housing may furthermore also incorporate cylinder openings for the operating cylinders and assume valve housing functions. All mechanical and pneumatic forces are supported in the carrier housing. The resulting reaction forces are supported via correspondingly predefined connection points on the manual transmission.
The carrier housing preferably has a basic housing, which can be closed by a cover, detachably fixed thereto by screws and which may be provided with a surface coating. Furthermore, the carrier housing may also contain travel sensors for determining the position of the control pistons, which can be connected to the electronic unit for evaluating the sensor signals. The electronic unit serves primarily for controlling the directional control valves integrated in the carrier housing. The control signals needed for this purpose are provided by an overriding control unit, preferably in the form of an external transmission and clutch control module, via the electrical wiring harness.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.